Pass data from a form to a controller in yii2 - yii2

Question

I am creating a page that has 3 fields - product code, startdate, enddate. When I click on the search button it should create a pdf file. 3 of these fields are without model.
I've tried code -
<?php
use yii\helpers\Html;
//use yii\grid\GridView;
use kartik\grid\GridView;
use kartik\export\ExportMenu;
use frontend\modules\stock\models\Sellitem;
use dosamigos\datepicker\DatePicker;
use dosamigos\datepicker\DateRangePicker;
use kartik\form\ActiveForm;
/* #var $this yii\web\View */
/* #var $searchModel frontend\modules\stock\models\SellitemSearch */
/* #var $dataProvider yii\data\ActiveDataProvider */
$this->title = 'Stock';
$this->params['breadcrumbs'][] = $this->title;
?>
<div class="sellitem-index">
<h1><?= Html::encode($this->title) ?></h1>
<?php // echo $this->render('_search', ['model' => $searchModel]); ?>
<div class="row">
<div class="form-group">
<div class="col-xs-4 col-sm-4 col-lg-4">
<label for="upc" class="control-label"><p class="text-info">Product Code <i class="icon-star"></i></p></label>
<input type="text" class="form-control" id="upc" class="span3">
</div>
<div class="col-xs-4 col-sm-4 col-lg-4">
<label for="upc" class="control-label"><p class="text-info">Start Date <i class="icon-star"></i></p></label>
<?= DatePicker::widget([
//'label' => 'Startdate',
'name' => 'startdate',
'id' => 'startdate',
//'value' => '02-16-2012',
'template' => '{addon}{input}',
'clientOptions' => [
'autoclose' => true,
'todayHighlight' => true,
'format' => 'yyyy-mm-dd'
]
]);?>
</div>
<div class="col-xs-4 col-sm-4 col-lg-4">
<label for="upc" class="control-label"><p class="text-info">End Date <i class="icon-star"></i></p></label>
<?= DatePicker::widget([
//'label' => 'Startdate',
'name' => 'enddate',
'id' => 'enddate',
//'value' => '02-16-2012',
'template' => '{addon}{input}',
'clientOptions' => [
'autoclose' => true,
'todayHighlight' => true,
'format' => 'yyyy-mm-dd'
]
]);?>
</div>
</div>
</div>
<p>
<div class="form-group pull-right">
<?= Html::a('Search', ['/stock/sellitem/stockbetweendates','upc'=> $upc, 'startdate'=> $startdate, 'enddate'=>$enddate],
['class'=>'btn btn-success'])
?>
</div>
</p>
</div>
This is giving error - undefined variable.
I've added $upc, $startdate, $enddate in the model but it's not helping. Please let me know what to do to pass these values to controller.
Controller Action
public function actionStockbetweendates($upc, $startdate, $enddate) {
$upc = yii::$app->request->get('upc');
$startdate = yii::$app->request->get('startdate');
$enddate = yii::$app->request->get('enddate');
// $modelProduction = Puritem::find()->where(['pi_upc' => $productname]);
// $searchModel1 = new PuritemsbSearch();
// $dataProvider1 = $searchModel1->search(Yii::$app->request->queryParams, $productname);
// $modelSell = Sellitem::find()->where(['si_iupc' => $productname]);
// $searchModel2 = new SellitemsbSearch();
// $dataProvider2 = $searchModel2->search(Yii::$app->request->queryParams, $productname);
// $content = $this->renderPartial('_printproductledger', [
// 'modelProduction' => $modelProduction,
// 'dataProvider1' => $dataProvider1,
// 'searchModel1' => $searchModel1,
// //'data'=> $data,
// 'modelSell' => $modelSell,
// 'searchModel2' => $searchModel2,
// 'dataProvider2' => $dataProvider2,
// 'productname' => $productname,
// 'prodesc' => $prodesc,
// ]);
// $footer = "<table name='footer' width=\"1000\">
// <tr>
// <td style='font-size: 18px; padding-bottom: 20px;' align=\"right\">Signature</td>
// </tr>
// </table>";
// $pdf = new Pdf([
// 'mode'=> Pdf::MODE_UTF8,
// 'format'=> Pdf::FORMAT_A4,
// 'destination'=> Pdf::DEST_BROWSER,
// 'orientation'=> Pdf::ORIENT_LANDSCAPE,
// //'destination' => Pdf::DEST_DOWNLOAD,
// 'cssFile' => '#vendor/kartik-v/yii2-mpdf/assets/kv-mpdf-bootstrap.min.css',
// // any css to be embedded if required
// 'cssInline' => '.kv-heading-1{font-size:18px}',
// // set mPDF properties on the fly
// 'options' => ['title' => 'Print Party Ledger'],
// //'options' => ['defaultfooterline' => 0,],
// 'options' => ['defaultheaderline' => 0,],
// // call mPDF methods on the fly
// 'methods' => [
// 'SetHeader'=>['Ledger'],
// //'SetFooter'=>[$footer],
// ],
// 'content' => $content,
// ]);
// return $pdf->render();
//return $this->render('_printSalarystatement', ['s_period' => $s_period]);
}
ActionIndex that renders to the index2 page
public function actionIndex2()
{
$searchModel = new SellitemSearch();
$dataProvider = $searchModel->search(Yii::$app->request->queryParams);
return $this->render('index2', [
'searchModel' => $searchModel,
'dataProvider' => $dataProvider,
]);
}

Answer 1

I'm not sure how it works without rendering... But anyway, to make them defined, you need to pass them to view file. The most common method (and I think the best by far) is to use $this->render() operation. At the end of of your public function actionStockbetweendates($upc, $startdate, $enddate) { add this:
return $this->render('index2', [
'upc' => $upc,
'startdate' => $startdate,
'enddate' => $enddate,
];
One side note: you don't need to use these:
$upc = yii::$app->request->get('upc');
$startdate = yii::$app->request->get('startdate');
$enddate = yii::$app->request->get('enddate');
They are already defined (used) in parameters.